Abstract
Having begun in the 1970s with the American Landsat program, the use of optical satellite images for civilian purposes has since experienced significant technological advancements. In the space of 10 years, the images provided by Earth observation satellites have gone from high to very high spatial resolution, from a decametric resolution to a submetric resolution. In addition, the new generation of satellites known as "agile" allow for the reduction of acquisition time above the same area, while providing a synoptic and multispectral view of the territory. Long reserved for scientific use, these data conquer new fields of application and are reaching a much wider audience, competing sometimes with aerial photography.